Service manual

Wells-Garnder Color Vector Monitor Guide
Page 30 of 73
Symptom: Waveform At IC901 Outputs; If Missing, Check:
• R914 and/or R927 (wrong value)
• R916 (broken wire)
Symptom: Waveform At Q906; If Missing, Check:
• R926 (open)
• Q906 (white wire open)
• Q905 (emitter open)
Symptom: Waveform At Q905; If Collector Wrong, Check:
• Q906 (broken black lead or broken wire at emitter)
Symptom: Waveform At R921; If Wrong, Check:
• Q906 (white and black leads interchanged at socket)
Symptom: IC901; If No Input Voltages, Check:
• Q900 (red and black leads reversed)
• ZD901 (check voltage drop)
• ZD900 (shorted)
Symptom: IC901; If Input Voltages Present, Check:
• R914 (may be open; will cause waveform at C911 to not be x1K range)
• C911 (open)
• C915 (open)
• C916 (open)
• R901 (open)
• R904 (open)
• R905 (open)
• R913 (open)
• R923 (open)
• R924 (open)
• Q900 (shorted; +25 line is grounded by this)
• Q904 (reversed, open, or missing)